The following description is provided to assist the understanding of the reader. None of the information provided or references cited is admitted to be prior art to the present invention.
Environmental and sustainability concerns have created a need for alternative or renewable energy systems. Solar energy is one type of renewable energy source, and the sun's energy can be collected in a variety of different ways. One is converting solar energy into thermal energy to heat a fluid, such as air or water. Another is converting solar energy to electricity using photovoltaic cells. A properly sized and installed solar energy collection system can be a practical alternative for acquiring energy needs.
The disadvantages of traditional products for these purposes are that they are heavy and difficult to install, many do not have good durability and environmental resistance, and many are difficult to mass produce economically. Such roofing and cladding surfaces tend to heat up over periods of exposure to sunlight, and the heat may then be transferred to the interior of the building. This can increase the expense of air conditioning and environmental control. Therefore, various methods of deflecting the heat, for example by providing reflective surfaces, are also known.
In some cases, exposure to sunlight can be beneficial because of the possibility of being able to photovoltaically generate electrical power. Generally, the collection of any significant amount of solar energy requires a large area of photovoltaic surface be exposed to unobscured sunlight. It is well known in the art that building roof tops and exterior wall cladding provide vast areas of unoccupied space where it is convenient and effective to position such photovoltaic surfaces. A series of photovoltaic panels may be mounted on a roof to generate electrical energy. This energy can be used as generated (wholly or in part), be stored wholly or in part (e.g. to batteries) and/or be converted to AC and be fed wholly or in part into the grid. An advantage in improved aesthetics, less weight, less panel materials and less exposure to wind can be achieved when such PV panels are integrated into the building cladding products. This can also reduce the total material and installation costs associated with a solar electricity system.
However, PV roofing and cladding products can be complex and costly to produce, especially in 3D polymer form and in large scale production. They can also lack durability, aesthetics and weather resistance that would otherwise be desirable in a roofing product. In terms of durability, many conventional PV roofing and cladding products are inherently unstable when exposed to sunlight for an extended period of time. Moreover, prior art photovoltaic roofing shingles are generally difficult to install. These products typically come as single tiles or shingles. Numerous tiles or shingles are required in an array to provide roof cladding. Such small tiles or shingles require electrical junctions between each of the photovoltaic cells. Such junctions can be time consuming to connect and are often a failure point of the product because they corrode or the connections are incorrectly made. A further difficulty is that some of the energy from the solar cells will simply be dissipated as heat. The hotter the cells get, the less efficiently they work, and the higher the heat transmission through the roof surface into the building. Because roofing tiles are often designed to insulate the rest of the house from getting too hot, they also tend to prevent the solar cells from cooling effectively.
Therefore, a need exists for thermal and/or photovoltaic roofing systems that are easy to manufacture, effectively utilize the sun's energy, are weatherproof, durable, aesthetically pleasing, and economical.
It is therefore an object of the present invention to provide a for thermal and/or photovoltaic roofing product and/or system which will go at least some way towards addressing the foregoing problems or which will at least provide the public with a useful choice.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.